User apparatus

A communication method by a terminal, the method comprising:

• communicating with a first base station apparatus and a second base station apparatus, wherein the first base station apparatus is a master node in a New Radio (NR) radio communication system and the second base station apparatus is a secondary node in the NR radio communication system;
• receiving from the first base station apparatus an instruction to measure a system frame number and frame timing difference (SFTD) representing a system frame number and frame timing difference between cells;
• controlling a transmission of the SFTD between a cell of the first base station apparatus and a cell of the second base station apparatus, the SFTD being measured based on the instruction to measure the SFTD;
• and
• transmitting to the first base station apparatus a measurement result including the measured SFTD using a parameter configuration that is the same as a parameter configuration of an SFTD measurement result in a case in which a master node is an Evolved Universal Terrestrial Radio Access (E-UTRA) radio communication system and a secondary node is an NR radio communication system, and
• wherein the instruction to measure SFTD includes information indicating that a Primary SCG Cell (PSCell) of the second base station apparatus or one or more neighboring cells of the second base station apparatus is a cell for which SFTD is to be measured.

A radio communication system comprising:

• a terminal;
• a first base station apparatus;
• and
• a second base station apparatus,
• wherein the terminal includes
• a communication unit configured to communicate with the first base station apparatus and the second base station apparatus, wherein the first base station apparatus is a master node in a New Radio (NR) radio communication system and the second base station apparatus is a secondary node in the NR radio communication system;
• a reception unit configured to receive from the first base station apparatus an instruction to measure a system frame number and frame timing difference (SFTD) representing a system frame number and frame timing difference between cells;
• a control unit configured to control a transmission of the SFTD between a cell of the first base station apparatus and a cell of the second base station apparatus, the SFTD being measured based on the instruction to measure the SFTD;
• and
• a transmission unit configured to transmit to the first base station apparatus a measurement result including the measured SFTD using a parameter configuration that is the same as a parameter configuration of an SFTD measurement result in a case in which a master node is an Evolved Universal Terrestrial Radio Access (E-UTRA) radio communication system and a secondary node is an NR radio communication system, and
• wherein the instruction to measure SFTD includes information indicating that a Primary SCG Cell (PSCell) of the second base station apparatus or one or more neighboring cells of the second base station apparatus is a cell for which SFTD is to be measured.